Refrigerating system



R. W. DAVENPORT REFRIGERATING SYSTEM Nov. 19, 1929.

Filed NOV. 29. 1927 0M (I I\- A TTORNE Y.

Patented :Nov. 19, 1929 UNITED. STATES PATENT FFICE RANSOM W. DAVENPORT, OF DETROIT, MICHIGAN, ASSIGNOR TO CHICAGO PNEUMATIC TOOL COMPANY, OF NEW YORK, Y., A CORPORATION OF NEW JERSEY REFRIGERATING SYSTEM:

Application filed November 29, 1927. Serial No. 236,428.

This invention relates to processes and apparatus for transforming heat with particular reference to refrigerating systems. More specifically it concerns refrigerating systems opcrating on the vapor-gas principle disclosed in my S. Patent N 0. 1,619,196 issued March Heretofore it has been proposed toutilize the vapor-gas principle for producing a variety of refrigerating temperatures in the same system, sometimes by providing a single evaporator taking heat from its surroundings at progressively higher temperatures as the top of the evaporator is approached, sometimes by providing one evaporator operating on the vapor-gas principle and another on the conventional Rankine cycle with both evaporators taking heat from the refrigerator but at difierent temperature levels. Among the objects of the invention are to adapt the vapor-gas principle of refrigeration to the cooling of brine and other single temperature operations, and in general to effect improvements and economies in processes and apparatus for securing such functions.

The present invention differs from previously known arrangements, both of the vapor-gas and of the conventional type, particularly in that While a plurality of evaporators are involved in a single system, one of the evaporators (the straight pumping one) takes heat from the liquid refrigerant between its exit from the condenser and its entrance into the low temperature zone and. the other evaporator takes heat from the substances to be cooled or frozen. This arrangement, therefore, is Well adapted to cooling brine for freezing Water or preserving ice cream or for other purposes in which it is requisite or desirable that the Whole refrigeration take place at a single temperature.

In order to illustrate the invention concrete embodiments thereof are shown in the accompanying drawings in which Fig. 1 is a diagrammatic illustration of one form of the system,

Fig. 2 is a diagrammatic view similar to Fig. 1 showing a modified arrangement; and

Fig. 3 is aside elevational view partly'in section of a practical embodiment of the system.

All forms of the system herein disclosed for illustrative purposes are arranged to utilize the vapor-gas principle disclosed in my U. S. Patent 1,619,196 above referred to. Consequently, the refrigerant medium consists of a volatile liquid or liquefied gas and a substantially incondensible gas which is inert to and insoluble in the liquid or its vapor. Any suitable liquid may be selected. If a very low temperature is desired volatile liquids or liquefied gases having a low boiling point may be utilized, such as ammonia,- sulphur dioxide and the like. If the desired temperature is only moderately low, and high operating pressures in the apparatus are to be avoided, liquids having a relative high boiling point may be chosen, such as the halogenated hydrocarbons including the ethyl and methyl chlorides.

While my improved process is susceptible of operation with systems'of the open cycle type, it is preferable to operate on a closed cycle. In the arrangement disclosed in Fig. 1 vapor and gas withdrawn through connection 4 by a pump or compressor. 5 argdischarged at higher temperature and pressure into a suitable condenser 6 where heat is extracted, the contents of the condenser being discharged into a chamber 7 where the residual vapor and gas are separated from the condensed liquid. The vapor and gas pass off through a connection 8 while the separated and warm liquid under control of a feeding member, such as float valve 9, passes through connection 10 into a container 11 having insulated walls 12. Container 11 is maintained under suction pressure of pump 5 through connection 4 to eifectcooling of the liquid contained therein by straight pumping. The cool liquid from container 11 passes through a connection 13 to evaporator 14 which contains a body of the volatile refrigerant liquid in thermal contact with-a body of low freezing liquid 15, such as brine. Thevapor and gas passing from separator chamber 7 through connection 8 areexpanded through a suitable restricted opening, such as a. Venturi nozzle 16, into the body of volatile has insulated walls 12.

up some of its heat to the liquid in container latter through the operation 0 liquid in evaporator 14 so that the latter operher for conducting separated gas and vapor ates on the vapor-gas principle. to an expansion or Venturi nozzle 24 so that The refrigerating effects produced by the evaporator 18 operates on the Vapor-gas prin-' above arrangement are as follows: The liquid ciple. Connection 19 between evaporator 18 in container 11 i cooled to a temperature and container 20 not only serves as an overapproximately corresponding with the total flow for liquid in the latter but places consuction pressure. This cooling is made practainer 20 under the suction pressure of the tically adiabatic by insulating the container pump so that liquid therein is cooled through or evaporator and no heat transfer is instraight pumping. A second connection 24*. volved. The cool liquid then passes through leads from the upper part of evaporator 18 connection 13 into the main evaporator 14 to a pump or compressor 25 which may be into which the vapor-gas expands through mounted with condenser 26 and operating nozzle 16. Here the liquid is cooled to apmo r 27 as an apparatus unit and disposed proximately the temperature corresponding at a distance fromcabinet A, either above with the partial vapor pressures obtaining in or belowthe latter. In the present instance evaporator 14, lthough th or-ga ix the unit is indicated as disposed in the baseture is withdrawn therefrom through pipe 4 m nt Wl h a connection 28 leading from the at the same total pressureas from container I1 nse1 to the top of the separating cham- 11. As the temperature thus obtained in be? ve float Valve 22. evaporator 14 is lower than that obtainable From the above, 113 Will be pp that in container 11, especially when high-boiling the p t i Il 'i arrange o adapt liquids are employed, and as the liquid which refrigerating systems operating on the vais fed to evaporator 14 has already been cooled P -g p in iple so s to producethe entire considerably, a lower temperature may be useful lg r ing effect at a slngle temint i d ithgiven t t l ti presperature, thatthls result is economically efsure that is possible with previously known fected by coohng the Warm condensate prior arrangements when applied to single temt0 l mlsslon to the vapor-gas evaporator, eratur wo k, that the pre-cooling of the liquid may be ef- In the modified arrangement shown in Fig. fected n ges by straight pumping, and

2, the separator chamber 7 a for the products h t both h traight pumping for the preof condenser 6 has no feed control device llmlnary evaporator and the greater refrigbut has a trapped connection 7 b with a chammg effect PI hI E 1n the final or Vaporber 7 disposed within the container 11 which g evaporator e P ace at the same total F di f li id pressure produced by the pump or comfrom the interconnected chambers 7 and 7 P e A is controlled by a float valve 9 in chamber Whlle my p d Process an pparatus 7 71th thi arrangement it i apparent for practicing the same have been herein disthat the separated liquid has already given closed 111 What, 110W consldered to be P ferred forms, 1t 1s to be understood that the b f it i f d i t th invention is not limited to the specific details or evaporator 11 f fl t valve thereof but covers all changes, modlficatlons 9. Once in container 11, the liquid is further cooled by the withdrawal of its vapor through pump connection 4 and this further cool'ed liquid passes through connection 13 to the vapor-gas evaporator 14. By this arrangement the preliminary cooling of refrigerant liquid is under high-side pressure and heat transfer is involved.

In the practical arrangement disclosed in Fig. 3, there is a still further modification. This figure discloses a refrigerator cabinet A suitable for household use having th a brine tank 17 for extracting heat from the interior of the cabinet. The brine 'tank has in its upper portion an evaporator 18 containing liquid refrigerant and connected by a pipe 19 to a container 20 for liquid having insulated walls. The upper portion of the products of the condenser. A connection container has a partition 21 with a port therethrough controlled by a float valve 22, the portion of the container above partition 21 serving as a separating chamber for the 23 leads from the top of the separating chamand adaptations within the scope of the appended claims.

I claim as my invention:

1. A refrigerating process utilizing as a Working medium an evaporable liquid and erein condensate toward the body of vaporizing liquid, separating the gas-vapor from the condensate, cooling the condensate by evaporating it under reduced pressure of its own vapor only and substantially without access 0 heat from surroundings, feeding the cooled condensate to the body of liquid, expanding the vapor-gas mixture into said body While reducing the pressure above said body, and continuously repeating the above steps.

2. A refrigerating system utilizing as a Working substance an evaporable liquid and a gas substantially inert to and insoluble in the liquid comprising, a compressor, a condenser, and an evaporator, said evaporator containing a body of said liquid, means for feeding vapor, gas and liquid from said condenser to said evaporator, means for separating at least a part of the condensed liquid from the vapor and gas issuing from said condenser, and means for cooling said separated liquid adiabatically by withdrawing vapor therefrom before feeding the liquid to said evaporator.

3. A refrigerating system utilizing as a working substance an evaporable liquid and a gas substantially inert to and insoluble in the liquid, comprising, a compressor, a condenser, and an evaporator, said evaporator containing a body of said liquid, and means for feeding vapor, gas and liquid from said condenser to said evaporator comprising means for separating at least a part of the condensed liquid from the vapor and gasfissuing from said condenser, a thermally'insulated container for said separated liquid,

a connection from said compressor to said container 'for withdrawing vapor of the liquid therefrom to cool the liquid, means permitting movement of the cooled liquid from said container to said evaporator, and means discharging the separated gas and vapor into said evaporator beneath the surface of the liquid therein to cause said evaporator to operate on the vapor-gas principle.

4. A refrigerating system utilizing as ,a working substance an evaporable liquid and a gas substantially inert to and insoluble in the liquid comprising, a compressor, a condenser, and an evaporator, said evaporator containing a body of said liquid, and means for feeding vapor, gas and liquid from said condenser to said evaporator comprising means for separating at least a part of the {sulated.cont'ainer for the condensed liquid,

condensed liquid from the vapor and gas issuing from said condenser, a thermally insulated container for said separated liquid,

'a connection from said compressor to said container for withdrawing vapor of the liquid therefrom tocool the liquid, means permitting movement of the cooled liquid from said container to said evaporator,- means discharging the separated gas and vapor into said evaporator beneath the surface of the liquid therein to cause said evaporator to operate on the vapor-gas principle, and a body of low freezing liquid in contact with said evaporator.

A refrigerating system utilizing as a working substance an evaporable liquid and a gas substantially inert to and insoluble in the liquid comprising, a compressor, aco'ndenser, and an evaporator, said evaporator containing a body of said liquid, and means for feeding vapor, gas and liquid from said condenser to said evaporator comprising means forseparating at least a part of the condensed liquid from the vapor and gas issuing from said condenser, a thermally insulated container for said separated liquid, a float device for controlling the feeding of liquid to said container, means utilizing said compressor to effect vaporization and consequent cooling of the liquid in said container, a connection from said container to said evaporator, and means utilizing both said compressor and the separated vapor and gas to effect absorption of heat by the liquid in said evaporator.

6. A refrigerating system utilizing an evaporable liquid and an inert gas comprising a compressor, a condenser, and an evaporator connected together to -form a closed cycle system, said evaporator containing a bodyof said liquid, said system providing a chamber into which said condenser dischargesfon s'eparating the residual gas and vapor fromjthe condensed liquid, a thermallyinsulatedicontainer into which the condensed liquid is fed, a connection from said container to said evaporator, means utilizing said compressor to effect coolingof the liquid in said container, and means utilizing both said compressor and said separated vapor and gas to effect a still greater cooling of the liquid in said evaporator. p

7. A refrigerating system utilizing an evaporable liquid and an inert gas comprising a compressor, a condenser, and an evaporator connected together to form a closed cycle system, said evaporator containing a body of said liquid, said system providing a chamber into which said condenser discharges for separating the residual gas and vapor from the condensed liquid, a connection from said chamber to the bottom of said evaporator for expanding the air and vapor into the body of liquid in said evaporator, a thermally inmeans controlling the feeding of the liquid from said chamber to said container, and connections from said container to said compressor and to said evaporator.

means providing for the feeding of liquid by gravity from said chamber to said container and thence tosaid evaporator, and a connection from the top of said container to said compressor to effect cooling of the liquid ii] said container by straight pumping.

9. A refrigerating system utilizing an evaporable liquid and an inert gas comprising a compressor, a condenser, and an evaporator connected together to form a closed cycle system, said evaporator containing a body of said liquid, said system providing a chamber into which said condenser, discharges forseparating the residual gas and vapor from the condensed liquid, a connection from said chamber to the bottom of said evaporator for expanding the air and vapor into the body of liquid in said evaporator, a thermally insulated container for 'the condenser liquid, means providing for the feeding of liquid by gravity from said chamber to said container and thence to said evaporator, a float device controlling the feeding of liquid from said chamber to said container, and a connection from the top of said container to said compressor to effect cooling of the liquid in said container by straight pumping.

10. A refrigerating system of the closed cycle type utilizing as a Working medium a volatile liquid and an inert gas comprising a compressor, a condenser, and an evaporator means for separating the condensed liquid from the gas and vapor issuing from said condenser, means for feeding the liquid by stages to said evaporator, means for cooling said liquid Without access of heat from surroundings during one of the stages by vaporizing a portion of the same through the action of said compressor, and means for expanding the separated gas and vapor into said evaporator to cause the latter to operate on' the vapor-gas principle.

11. A refrigerating system of the closed cycle type utilizing as a working medium a volatile liquid and an inert gas comprising cooled liquid from the first evaporator to the second evaporator.

Signed by me at Detroit, in the county of Wayne and State of Michigan this 17 day of November, 1927.

RANSOMW. DAVENPORT.

a compressor, a condenser, and an evaporator,

means for separating the condensed liquid from the gas and vapor issuing from said condenser, means for feeding theliquid by stages to said evaporator, means for cooling said liquid Without transfer of heat from surroundings during, one of the stages by vaporizing a portion of the same through the action of said compressor, a body of brine in thermal contact with said evaporator, and means for expanding the separated gas and vapor into said evaporator to cause the latter to operate on the vapor-gas principle.

12. In a refrigerating system of the closed cycle type utilizingan evaporable liquid and an inert gas, a plurality of evaporators containing the liquid, means for reducing the pressure in said evaporators to cause the liquid therein to vaporize and arranged to operate one of said evaporator-s by straight pumping and another evaporator on the vapor-gas principle, meansfor insulating the first evaporator against access. of heat. from surroundings, and means for feeding 

